Recent allegations about Russian attempts to poison its enemies have left the whistle-blower at the centre of the country's doping scandal "looking over his shoulder", his lawyer has revealed.
The former head of the Moscow anti-doping laboratory, Dr Grigory Rodchenkov, fled Russia in late 2015 when a World Anti-Doping Agency-funded investigation corroborated reports of endemic doping in Russian athletics and two of his former colleagues died in mysterious circumstances.
Having gone into hiding in the United States, Rodchenkov reemerged in 2016 to reveal the state-sponsored conspiracy to cheat involved hundreds of athletes, from almost all sports, between 2010 and 2015. These claims were confirmed by a second WADA investigation and the International Olympic Committee.
On Monday, his lawyer Jim Walden revealed that Rodchenkov was taking legal action in New York to have a libel case against him - brought by three Russian biathletes - dismissed as frivolous and start his own lawsuit against the man financing the libel case, Russian oligarch Mikhail Prokhorov.
In a statement issued via Walden, Rodchenkov thanked his lawyers, said he was "healthy and well protected" and confirmed his intention to cooperate with the authorities.
"Despite Russia's recent disinformation campaign, all of the information I gave to the IOC and WADA was completely accurate, and I did not retract a word of it," he said.
"I will continue to fight for clean athletes and for reform, even as international agencies desperately try to find a way to allow Russia to turn the page."
Asked if his client was more worried for his safety after the poisoning attack on ex-Russian intelligence officer Sergei Skripal and his daughter Yulia in Salisbury last month, Walden referenced another recent story - an alleged attempt to poison ex-BP chief executive Bob Dudley in Russia a decade ago - and said: "We are extremely concerned".
Walden described these two cases as "just the most recent examples of Russia's blatant criminality".
He said: "For as long as the current regime is in power in Russia, Grigory Rodchenkov will always be looking over his shoulder."
The two lawsuits Walden and his colleagues are bringing on behalf of Rodchenkov are an attempt to hit back at the €24m libel suit Olga Zaytseva, Yana Romanova and Olga Vilukhina have filed against the former lab director.
Prokhorov, the president of the Russian Biathlon Union and the owner of the National Basketball Association's Brooklyn Nets, has made little secret of the fact he is funding this lawsuit.
Rodchenkov's legal team want the US courts to dismiss the suit immediately and have countered with their own multi-million-dollar claim against Prokhorov, one of Russia's richest men, based on New York law that protects whistle-blowers.
On the recent Russian reports that Rodchenkov has either retracted his testimony or it has been rejected by the Court of Arbitration for Sport (CAS), Walden dismissed them out of hand as "spin from Kremlin puppets" and "lies, plain and simple".
He said the CAS decisions to overturn the life bans of 28 Russians accused of doping at Sochi 2014 was not an exoneration, it was merely a case of the court not being able to meet the "high evidential bar for personal culpability".
"Grigory has been credible and consistent throughout and the fact CAS upheld the convictions of 11 other Russians fully corroborates his testimony," said Walden.
The lawyer added that Rodchenkov has more information to share on the recent revelations that the International Biathlon Union tried to cover up Russian doping cases.